Effective Na+ fluorescent sensing by new podand-type receptor connecting two pyrene units and diphenyl ether

Abstract

A new podand-type receptor for Na + detection has been synthesized by connecting two 1-pyrenecarbonylmethyl groups with two hydroxy groups of 2,2'-dihydroxydiphenyl ether. With the addition of Na + in the range of 20-200 µM, the increasing monomer emission (423 nm) and the decreasing excimer emission (524 nm) of pyrene were observed. In contrast with the receptor, the fluorescence spectra of the corresponding compound obtained from 2,2'-dihydroxydiphenylmethane are only slightly affected by the addition of Na + .

Optical probes for the detection of protons, and alkali and alkaline earth metal cations

“…39 formed a 1 : 1 complex with Na + with a binding constant of 1.14 Â 10 4 M À1 and showed good selectivity over other physiologically relevant cations. 49 The use of a polyamidoamine (PAMAM) dendrimer 40, having sixteen 1,8-naphthalimide fragments in its periphery was developed for the selective fluorescent 'turn-on' sensing of Li + in alkaline DMF medium without any interfering effects from the other alkali metal ions such as Na + and K + . 50 Following this report, Lamy and coworkers have developed a new Na + sensitive nanoprobe (diameter = 6.57 AE 0.04 nm) by encapsulating a Na + dye CoroNa Green (CG) non-covalently in a PAMAM dendrimer (generation 5) nanocontainer carrying a poly(ethyleneglycol) surface (PAMAM-PEG) for imaging neuronal activity in whole brain tissue.…”